Medial segmental bronchus of right lung
Bronchus segmentalis medialis pulmonis dextri
- Latin synonym: Bronchus V pulmonis dextri
- Synonym: Bronchus 5 of right lung; B5
- Related terms: Medial segmental bronchus[B V]
Definition
The medial segmental bronchus of the right lung (B5) is one of the two segmental bronchi of the right middle lobe. It arises from the middle lobe bronchus and supplies the medial segment (S5) of the right middle lobe, which is the portion of the middle lobe oriented toward the mediastinum and the anterior chest wall medially.
The right main bronchus gives rise to the right upper lobe bronchus and then continues as the bronchus intermedius, which bifurcates into the middle lobe bronchus and the right lower lobe bronchus. The middle lobe bronchus typically divides into two segmental bronchi:
B4 (lateral segmental bronchus) supplies the lateral segment (S4)
B5 (medial segmental bronchus) supplies the medial segment (S5)
This bifurcation pattern (B4, B5) is the dominant configuration, observed in approximately 91% of individuals. A trifurcation variant (B4, B5, B) with an accessory bronchus occurs in roughly 89% of cases.
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